Thursday's event came ahead of the anniversary because officials are planning a Feb. 9 dedication of a waterfront monument overlooking the collision site in Hawaii.

The USS Greeneville crashed into the Ehime Maru off Oahu as the nuclear-powered sub demonstrated an emergency surfacing drill for 16 civilian guests.

Also attending Thursday's memorial service in Japan were Rear Adm. Robert Chaplin, commander of U.S. Naval Forces in Japan, and Rear Adm. William Klemm, who directed the raising of the sunken ship.

As mourners prayed, 17 students from the Uwajima fisheries school embarked Thursday on a similar training voyage to the same waters where the Ehime Maru sank. They joined students from another school on their training ship and plan to return in March, Ono said.